Numerous variations of metal and plastic conveyor belts are used in today's conveyor belt applications. Each type of belt and belt material has its own benefits for the various conveyor belt applications. Plastic conveyor belts are known for being easy to install and repair. Designs for the edges of the plastic conveyor belts are such that the belts can be easily disassembled and reassembled without having to replace the components or use any special tools.
Historically, metal belts have often been preferred for applications that require high temperature, a need for a large amount of open area, and/or a need to sanitize the belt. However, one of the main disadvantages of metal belts has been the requirement to weld the edges of the belt during installation and repair. Furthermore, when a metal belt requires repair, some components of the belt cannot be reused, but must be replaced to return the belt to service. This means stocking additional belt components for the inevitable repairs, or waiting to receive those components from the belt supplier. Making repairs to metal belts often necessitates grinding and welding operations. Grinding results in metal dust and debris which can create sanitation issues, and welding usually requires a “hot work” permit along with special provisions to avoid a fire within the facility. Both operations typically create issues for the plant maintenance manager that should be avoided if possible.
One of the most commonly used types of conveyor belts for carrying diverse products along both straight and horizontally curved paths is a grid conveyor belt. Examples of conventional grid conveyor belts are the Cam-Grid® and the heavy duty Cam-Grid® conveyor belts available from Cambridge International, Inc., the assignee of the present invention. A grid conveyor belt, as shown generally in U.S. Pat. No. 6,354,432, the entire contents of which are hereby incorporated by reference, includes a plurality of spaced transverse rods slidably interconnected by at least two rows of U-shaped connecting links, i.e., the tension bearing members, disposed respectively along the inner and outer edges of the rods. The terminal ends of the transverse rods are formed into enlarged heads or button heads which retain the links on the rods and welds are then provided to secure the link to the button head and to the rod, thereby preventing rotational movement of the links on the transverse rods. The connecting links are disposed in a nested relationship relative to one another with slots being provided in the links in order to slidably receive the transverse rods.
Grid conveyor belts of this type have met with overwhelming market approval because of their ability to travel in straight line conveyor paths as well as in curved conveyor paths, thus making grid conveyor belts ideal for use on spiral cage conveyors. However, when the belt is in need of repair due to breakage or maintenance, the presence of the button head ends and welded ends requires the use of special tools such as a grinder and bolt cutter and welding in order to part an endless belt or to reconnect or splice two separate ends of a belt. In addition, special threaded connector rods with end nuts have to be used to replace the rods with the button head ends when performing repair/maintenance in the field.
Flat wire conveyor belts have also been in the market for many years, as shown for example in U.S. Pat. Nos. 2,619,306 and 7,721,877, the contents of which are hereby incorporated by reference. Flat wire conveyor belts are generally low maintenance and when positively driven with sprockets have little to no lateral shifting. With reference to FIG. 1A, there is disclosed a flat wire conveyor belt 10 comprising a plurality of connecting rods 12. In the illustrated embodiment, the conveyor belt 10 also includes a plurality of pickets 16, sometimes also referred to as wickets, which hinge about the connecting rods 12. The pickets of the belt define the tension bearing members and support the product to be conveyed and the rods are utilized to hold the components of belt together. This example of a flat wire conveyor belt also includes a plurality of edge bar links 14 and upset rod ends 18, i.e., button head shaped ends, for rod retention. The compression between the pickets keep them from moving inward of the button head ends, while the button head ends prevent the pickets from moving outwardly. Flat wire conveyor belts of this type can also be used in both straight and turn applications.
Flat wire conveyor belts have similarly met with long term market approval. However, when the belt is in need of repair due to breakage or maintenance, the presence of the button head or clinched rod ends requires the use of special tools such as a grinder or bolt cutters and welding or special hand tools in order to part an endless belt or to reconnect or splice two separate ends of a belt. In addition, special threaded or partially clinched connector rods with end nuts have to be used to replace the rods when performing repair/maintenance in the field.
With reference to FIG. 1B, the eye link conveyor belt 20 is constructed of small eyelets 22, which may be welded onto a cross wire 23 to form segments generally 4-12 inches in width, which are then cut-down as needed and brick-laid assembled with other components such as reinforcing/support bars 18 (bar links) to form a row of segments and components which are then linked to adjacent rows with hinge point connecting rods 16 (cross rods).
The major disadvantages of eye link style belts have been that the belt is constructed of components such as the reinforcing/support bars 18 that not only make the belt very expensive and time consuming to assemble but also make it more difficult to splice and maintain the conveyor belt in the field.
While market trends are dictating that improvements be made to reduce conveyor system down time, employers are finding that maintenance resources are decreasing in both quantity and skill base. Accordingly, there exists a need in the marketplace for a metal conveyor belt having a splice link that can quickly and easily be used to splice together and repair a conveyor belt with a minimal use of tools or skill, all while retaining the important features typically found in the metal belt.